I. Field of the Invention
The present invention relates to a custom dental impression tray for both crown and bridge prosthesis as well as dentures.
II. Description of the Prior Art
Dental impression trays are necessary to construct both crown and bridge prosthesis as well as dentures. Furthermore, since the human mouth varies from one patient to the next, it is necessary for the dentist to make a custom impression tray before the bridge, crown or dentures can be constructed.
In the previously known methods for constructing custom impression trays, a preliminary model of the mouth is first made by the dentist. Typically, the dentist selects a standard tray which fits within the area of the mouth being treated. This tray is then filled with alginate, pressed into the patient's mouth and allowed to set. Thereafter, the tray is removed and filled with plaster in order to form the preliminary model of the patient's teeth and/or mouth.
After the preliminary plaster model has hardened, thin separating sheets, typically constructed of asbestos, are molded onto the preliminary model in order to form a small space between the teeth or gum area on the model and the outside of the separating sheets.
Thereafter, powdered acrylic and liquid monomer are mixed together until the mixture reaches a putty consistency. The mixture is then molded into a patty which is then molded around the separating sheets of the preliminary model. Upon hardening, the molded acrylic and monomer forms the custom tray.
After the custom tray has hardened, dental impression material is placed in the tray and then positioned within the patient's mouth. The dental impression material fills the space represented by the separating sheets on the preliminary model and, upon hardening, forms a final impression of the desired area of the patient's mouth. The crown, bridge work and/or dentures are formed from this final impression of the patient's mouth.
A primary disadvantage of this previously known method for forming custom dental impression trays is that the procedure is time consuming and tedious. Furthermore, in view of the materials employed and the multiple steps necessary to obtain the custom dental impression tray, this previously known procedure is expensive in material costs.